Beautiful sphere of red tiger's eye (cat's eye)

A hand-polished sphere of red tiger's eye, also called cat's eye, from South Africa. The sphere displays an intense red-brown coloration and a silky, shimmering luster across its polished surface.

Tiger's eye is a pseudomorph variety of quartz after the fibrous mineral crocidolite. The red variant is formed by heating or by natural iron oxide admixtures, which shift the originally golden-brown material to a reddish tone.

The eponymous chatoyance effect is created by the parallel fibrous structure of the material, which causes a band of light to move perpendicular to the fiber direction. The spherical shape makes the effect particularly clear, as the band of light moves with the rotation.